Linear Model, please help! urgent!

[AMV]

Linear Model

UPDATE: I figured it out! I was off by one step, haha. Thanks for the reply's, though!

Gasoline mileage of automobiles is influenced by the horsepower of the automobile. Below is a table of the data, use the data table to answer the following question:

HP(x) 49|52|55|58|61|64|67
MPG(y) 65.4|56.5|46.0|49.2|40.3|39.4|36.1

QUESTION: Find a linear model that fits the data, round to four decimal places



Just an FYI, I know how to find linear models, but this one has gotten me completely confused. I know I need to start off with finding the slope, which I've tried, and continued to get wrong (the answer is in the back of the book). Does it have something to do with the fact that the first difference isn't equally separated? Please Help!!

 

[tkhunny]

What have you tried?

Are you trying to find a collocating linear model? Good luck with that.

Did you draw a scatter plot? It may give you a sense of it.

It took me almost 45 seconds on MS Excel, including the time to enter the data. Can you use such tools?

What's the answer in the book?

Frankly, that doesn't look all that linear to me. I'd try a quadratic model, but you probably shoudl stick to the problem statement.

 

[AMV]

that answer is y=-1.5214x+135.8
i start out trying to find the slope, just like most linear models, and I end up having to stop there, because I never get -1.5214


Yeah, we can use Excel to double check our answers, but we can't just put what excel gives us as an answer, gotta show the steps to how we got there.
I have literally never been this aggravated over math, but it seems like no matter what I do, I get a different answer than the one in the back of the book!:|